LCOV - code coverage report
Current view: top level - fs/xfs/scrub - bitmap.c (source / functions) Hit Total Coverage
Test: fstests of 6.5.0-rc4-xfsa @ Mon Jul 31 20:08:27 PDT 2023 Lines: 134 139 96.4 %
Date: 2023-07-31 20:08:27 Functions: 22 22 100.0 %

          Line data    Source code
       1             : // SPDX-License-Identifier: GPL-2.0-or-later
       2             : /*
       3             :  * Copyright (C) 2018-2023 Oracle.  All Rights Reserved.
       4             :  * Author: Darrick J. Wong <djwong@kernel.org>
       5             :  */
       6             : #include "xfs.h"
       7             : #include "xfs_fs.h"
       8             : #include "xfs_shared.h"
       9             : #include "xfs_bit.h"
      10             : #include "xfs_format.h"
      11             : #include "xfs_trans_resv.h"
      12             : #include "xfs_mount.h"
      13             : #include "xfs_btree.h"
      14             : #include "scrub/scrub.h"
      15             : #include "scrub/bitmap.h"
      16             : 
      17             : #include <linux/interval_tree_generic.h>
      18             : 
      19             : struct xbitmap_node {
      20             :         struct rb_node  bn_rbnode;
      21             : 
      22             :         /* First set bit of this interval and subtree. */
      23             :         uint64_t        bn_start;
      24             : 
      25             :         /* Last set bit of this interval. */
      26             :         uint64_t        bn_last;
      27             : 
      28             :         /* Last set bit of this subtree.  Do not touch this. */
      29             :         uint64_t        __bn_subtree_last;
      30             : };
      31             : 
      32             : /* Define our own interval tree type with uint64_t parameters. */
      33             : 
      34             : #define START(node) ((node)->bn_start)
      35             : #define LAST(node)  ((node)->bn_last)
      36             : 
      37             : /*
      38             :  * These functions are defined by the INTERVAL_TREE_DEFINE macro, but we'll
      39             :  * forward-declare them anyway for clarity.
      40             :  */
      41             : static inline void
      42             : xbitmap_tree_insert(struct xbitmap_node *node, struct rb_root_cached *root);
      43             : 
      44             : static inline void
      45             : xbitmap_tree_remove(struct xbitmap_node *node, struct rb_root_cached *root);
      46             : 
      47             : static inline struct xbitmap_node *
      48             : xbitmap_tree_iter_first(struct rb_root_cached *root, uint64_t start,
      49             :                         uint64_t last);
      50             : 
      51             : static inline struct xbitmap_node *
      52             : xbitmap_tree_iter_next(struct xbitmap_node *node, uint64_t start,
      53             :                        uint64_t last);
      54             : 
      55 51384834899 : INTERVAL_TREE_DEFINE(struct xbitmap_node, bn_rbnode, uint64_t,
      56             :                 __bn_subtree_last, START, LAST, static inline, xbitmap_tree)
      57             : 
      58             : /* Iterate each interval of a bitmap.  Do not change the bitmap. */
      59             : #define for_each_xbitmap_extent(bn, bitmap) \
      60             :         for ((bn) = rb_entry_safe(rb_first(&(bitmap)->xb_root.rb_root), \
      61             :                                    struct xbitmap_node, bn_rbnode); \
      62             :              (bn) != NULL; \
      63             :              (bn) = rb_entry_safe(rb_next(&(bn)->bn_rbnode), \
      64             :                                    struct xbitmap_node, bn_rbnode))
      65             : 
      66             : /* Clear a range of this bitmap. */
      67             : int
      68  1170165811 : xbitmap_clear(
      69             :         struct xbitmap          *bitmap,
      70             :         uint64_t                start,
      71             :         uint64_t                len)
      72             : {
      73  1170165811 :         struct xbitmap_node     *bn;
      74  1170165811 :         struct xbitmap_node     *new_bn;
      75  1170165811 :         uint64_t                last = start + len - 1;
      76             : 
      77  1204270504 :         while ((bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last))) {
      78    34125860 :                 if (bn->bn_start < start && bn->bn_last > last) {
      79          30 :                         uint64_t        old_last = bn->bn_last;
      80             : 
      81             :                         /* overlaps with the entire clearing range */
      82          30 :                         xbitmap_tree_remove(bn, &bitmap->xb_root);
      83          30 :                         bn->bn_last = start - 1;
      84          30 :                         xbitmap_tree_insert(bn, &bitmap->xb_root);
      85             : 
      86             :                         /* add an extent */
      87          30 :                         new_bn = kmalloc(sizeof(struct xbitmap_node),
      88             :                                         XCHK_GFP_FLAGS);
      89          30 :                         if (!new_bn)
      90             :                                 return -ENOMEM;
      91          30 :                         new_bn->bn_start = last + 1;
      92          30 :                         new_bn->bn_last = old_last;
      93          30 :                         xbitmap_tree_insert(new_bn, &bitmap->xb_root);
      94    34125800 :                 } else if (bn->bn_start < start) {
      95             :                         /* overlaps with the left side of the clearing range */
      96      758906 :                         xbitmap_tree_remove(bn, &bitmap->xb_root);
      97      758906 :                         bn->bn_last = start - 1;
      98      758906 :                         xbitmap_tree_insert(bn, &bitmap->xb_root);
      99    33366894 :                 } else if (bn->bn_last > last) {
     100             :                         /* overlaps with the right side of the clearing range */
     101       21139 :                         xbitmap_tree_remove(bn, &bitmap->xb_root);
     102       21139 :                         bn->bn_start = last + 1;
     103       21139 :                         xbitmap_tree_insert(bn, &bitmap->xb_root);
     104       21139 :                         break;
     105             :                 } else {
     106             :                         /* in the middle of the clearing range */
     107    33345755 :                         xbitmap_tree_remove(bn, &bitmap->xb_root);
     108    33345759 :                         kfree(bn);
     109             :                 }
     110             :         }
     111             : 
     112             :         return 0;
     113             : }
     114             : 
     115             : /* Set a range of this bitmap. */
     116             : int
     117  1137634810 : xbitmap_set(
     118             :         struct xbitmap          *bitmap,
     119             :         uint64_t                start,
     120             :         uint64_t                len)
     121             : {
     122  1137634810 :         struct xbitmap_node     *left;
     123  1137634810 :         struct xbitmap_node     *right;
     124  1137634810 :         uint64_t                last = start + len - 1;
     125  1137634810 :         int                     error;
     126             : 
     127             :         /* Is this whole range already set? */
     128  1137634810 :         left = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
     129  1137455332 :         if (left && left->bn_start <= start && left->bn_last >= last)
     130             :                 return 0;
     131             : 
     132             :         /* Clear out everything in the range we want to set. */
     133  1137455332 :         error = xbitmap_clear(bitmap, start, len);
     134  1137275459 :         if (error)
     135             :                 return error;
     136             : 
     137             :         /* Do we have a left-adjacent extent? */
     138  1137301321 :         left = xbitmap_tree_iter_first(&bitmap->xb_root, start - 1, start - 1);
     139  1137003555 :         ASSERT(!left || left->bn_last + 1 == start);
     140             : 
     141             :         /* Do we have a right-adjacent extent? */
     142  1137003555 :         right = xbitmap_tree_iter_first(&bitmap->xb_root, last + 1, last + 1);
     143  1135965482 :         ASSERT(!right || right->bn_start == last + 1);
     144             : 
     145  1135965482 :         if (left && right) {
     146             :                 /* combine left and right adjacent extent */
     147      355410 :                 xbitmap_tree_remove(left, &bitmap->xb_root);
     148      355409 :                 xbitmap_tree_remove(right, &bitmap->xb_root);
     149      355410 :                 left->bn_last = right->bn_last;
     150      355410 :                 xbitmap_tree_insert(left, &bitmap->xb_root);
     151      355410 :                 kfree(right);
     152  1135610072 :         } else if (left) {
     153             :                 /* combine with left extent */
     154     5199161 :                 xbitmap_tree_remove(left, &bitmap->xb_root);
     155     5199169 :                 left->bn_last = last;
     156     5199169 :                 xbitmap_tree_insert(left, &bitmap->xb_root);
     157  1130410911 :         } else if (right) {
     158             :                 /* combine with right extent */
     159     4528710 :                 xbitmap_tree_remove(right, &bitmap->xb_root);
     160     4528659 :                 right->bn_start = start;
     161     4528659 :                 xbitmap_tree_insert(right, &bitmap->xb_root);
     162             :         } else {
     163             :                 /* add an extent */
     164  1125882201 :                 left = kmalloc(sizeof(struct xbitmap_node), XCHK_GFP_FLAGS);
     165  1126260137 :                 if (!left)
     166             :                         return -ENOMEM;
     167  1126260137 :                 left->bn_start = start;
     168  1126260137 :                 left->bn_last = last;
     169  1126260137 :                 xbitmap_tree_insert(left, &bitmap->xb_root);
     170             :         }
     171             : 
     172             :         return 0;
     173             : }
     174             : 
     175             : /* Free everything related to this bitmap. */
     176             : void
     177    22408732 : xbitmap_destroy(
     178             :         struct xbitmap          *bitmap)
     179             : {
     180    22408732 :         struct xbitmap_node     *bn;
     181             : 
     182  1112074202 :         while ((bn = xbitmap_tree_iter_first(&bitmap->xb_root, 0, -1ULL))) {
     183  1089530000 :                 xbitmap_tree_remove(bn, &bitmap->xb_root);
     184  1087742807 :                 kfree(bn);
     185             :         }
     186    22408450 : }
     187             : 
     188             : /* Set up a per-AG block bitmap. */
     189             : void
     190    22395418 : xbitmap_init(
     191             :         struct xbitmap          *bitmap)
     192             : {
     193    22395418 :         bitmap->xb_root = RB_ROOT_CACHED;
     194    22395418 : }
     195             : 
     196             : /*
     197             :  * Remove all the blocks mentioned in @sub from the extents in @bitmap.
     198             :  *
     199             :  * The intent is that callers will iterate the rmapbt for all of its records
     200             :  * for a given owner to generate @bitmap; and iterate all the blocks of the
     201             :  * metadata structures that are not being rebuilt and have the same rmapbt
     202             :  * owner to generate @sub.  This routine subtracts all the extents
     203             :  * mentioned in sub from all the extents linked in @bitmap, which leaves
     204             :  * @bitmap as the list of blocks that are not accounted for, which we assume
     205             :  * are the dead blocks of the old metadata structure.  The blocks mentioned in
     206             :  * @bitmap can be reaped.
     207             :  *
     208             :  * This is the logical equivalent of bitmap &= ~sub.
     209             :  */
     210             : int
     211      479355 : xbitmap_disunion(
     212             :         struct xbitmap          *bitmap,
     213             :         struct xbitmap          *sub)
     214             : {
     215      479355 :         struct xbitmap_node     *bn;
     216      479355 :         int                     error;
     217             : 
     218      958710 :         if (xbitmap_empty(bitmap) || xbitmap_empty(sub))
     219             :                 return 0;
     220             : 
     221    25591473 :         for_each_xbitmap_extent(bn, sub) {
     222    24894123 :                 error = xbitmap_clear(bitmap, bn->bn_start,
     223    24894123 :                                 bn->bn_last - bn->bn_start + 1);
     224    24894123 :                 if (error)
     225           0 :                         return error;
     226             :         }
     227             : 
     228             :         return 0;
     229             : }
     230             : 
     231             : /*
     232             :  * Record all btree blocks seen while iterating all records of a btree.
     233             :  *
     234             :  * We know that the btree query_all function starts at the left edge and walks
     235             :  * towards the right edge of the tree.  Therefore, we know that we can walk up
     236             :  * the btree cursor towards the root; if the pointer for a given level points
     237             :  * to the first record/key in that block, we haven't seen this block before;
     238             :  * and therefore we need to remember that we saw this block in the btree.
     239             :  *
     240             :  * So if our btree is:
     241             :  *
     242             :  *    4
     243             :  *  / | \
     244             :  * 1  2  3
     245             :  *
     246             :  * Pretend for this example that each leaf block has 100 btree records.  For
     247             :  * the first btree record, we'll observe that bc_levels[0].ptr == 1, so we
     248             :  * record that we saw block 1.  Then we observe that bc_levels[1].ptr == 1, so
     249             :  * we record block 4.  The list is [1, 4].
     250             :  *
     251             :  * For the second btree record, we see that bc_levels[0].ptr == 2, so we exit
     252             :  * the loop.  The list remains [1, 4].
     253             :  *
     254             :  * For the 101st btree record, we've moved onto leaf block 2.  Now
     255             :  * bc_levels[0].ptr == 1 again, so we record that we saw block 2.  We see that
     256             :  * bc_levels[1].ptr == 2, so we exit the loop.  The list is now [1, 4, 2].
     257             :  *
     258             :  * For the 102nd record, bc_levels[0].ptr == 2, so we continue.
     259             :  *
     260             :  * For the 201st record, we've moved on to leaf block 3.
     261             :  * bc_levels[0].ptr == 1, so we add 3 to the list.  Now it is [1, 4, 2, 3].
     262             :  *
     263             :  * For the 300th record we just exit, with the list being [1, 4, 2, 3].
     264             :  */
     265             : 
     266             : /* Mark a btree block to the agblock bitmap. */
     267             : STATIC int
     268    34529865 : xagb_bitmap_visit_btblock(
     269             :         struct xfs_btree_cur    *cur,
     270             :         int                     level,
     271             :         void                    *priv)
     272             : {
     273    34529865 :         struct xagb_bitmap      *bitmap = priv;
     274    34529865 :         struct xfs_buf          *bp;
     275    34529865 :         xfs_fsblock_t           fsbno;
     276    34529865 :         xfs_agblock_t           agbno;
     277             : 
     278    34529865 :         xfs_btree_get_block(cur, level, &bp);
     279    34529856 :         if (!bp)
     280             :                 return 0;
     281             : 
     282    34529856 :         fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
     283    34529856 :         agbno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
     284             : 
     285    34529856 :         return xagb_bitmap_set(bitmap, agbno, 1);
     286             : }
     287             : 
     288             : /* Mark all (per-AG) btree blocks in the agblock bitmap. */
     289             : int
     290      971633 : xagb_bitmap_set_btblocks(
     291             :         struct xagb_bitmap      *bitmap,
     292             :         struct xfs_btree_cur    *cur)
     293             : {
     294      971633 :         return xfs_btree_visit_blocks(cur, xagb_bitmap_visit_btblock,
     295             :                         XFS_BTREE_VISIT_ALL, bitmap);
     296             : }
     297             : 
     298             : /*
     299             :  * Record all the buffers pointed to by the btree cursor.  Callers already
     300             :  * engaged in a btree walk should call this function to capture the list of
     301             :  * blocks going from the leaf towards the root.
     302             :  */
     303             : int
     304  3606232842 : xagb_bitmap_set_btcur_path(
     305             :         struct xagb_bitmap      *bitmap,
     306             :         struct xfs_btree_cur    *cur)
     307             : {
     308  3606232842 :         int                     i;
     309  3606232842 :         int                     error;
     310             : 
     311  3631996991 :         for (i = 0; i < cur->bc_nlevels && cur->bc_levels[i].ptr == 1; i++) {
     312    25764176 :                 error = xagb_bitmap_visit_btblock(cur, i, bitmap);
     313    25764149 :                 if (error)
     314           0 :                         return error;
     315             :         }
     316             : 
     317             :         return 0;
     318             : }
     319             : 
     320             : /* How many bits are set in this bitmap? */
     321             : uint64_t
     322      700886 : xbitmap_hweight(
     323             :         struct xbitmap          *bitmap)
     324             : {
     325      700886 :         struct xbitmap_node     *bn;
     326      700886 :         uint64_t                ret = 0;
     327             : 
     328     3261882 :         for_each_xbitmap_extent(bn, bitmap)
     329      930054 :                 ret += bn->bn_last - bn->bn_start + 1;
     330             : 
     331      700888 :         return ret;
     332             : }
     333             : 
     334             : /* Call a function for every run of set bits in this bitmap. */
     335             : int
     336    10009919 : xbitmap_walk(
     337             :         struct xbitmap          *bitmap,
     338             :         xbitmap_walk_fn         fn,
     339             :         void                    *priv)
     340             : {
     341    10009919 :         struct xbitmap_node     *bn;
     342    10009919 :         int                     error = 0;
     343             : 
     344    30805928 :         for_each_xbitmap_extent(bn, bitmap) {
     345     5523716 :                 error = fn(bn->bn_start, bn->bn_last - bn->bn_start + 1, priv);
     346     5523722 :                 if (error)
     347             :                         break;
     348             :         }
     349             : 
     350    10009931 :         return error;
     351             : }
     352             : 
     353             : /* Does this bitmap have no bits set at all? */
     354             : bool
     355        9261 : xbitmap_empty(
     356             :         struct xbitmap          *bitmap)
     357             : {
     358      479355 :         return bitmap->xb_root.rb_root.rb_node == NULL;
     359             : }
     360             : 
     361             : /* Is the start of the range set or clear?  And for how long? */
     362             : bool
     363  1074440540 : xbitmap_test(
     364             :         struct xbitmap          *bitmap,
     365             :         uint64_t                start,
     366             :         uint64_t                *len)
     367             : {
     368  1074440540 :         struct xbitmap_node     *bn;
     369  1074440540 :         uint64_t                last = start + *len - 1;
     370             : 
     371  1074440540 :         bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
     372  1074342321 :         if (!bn)
     373             :                 return false;
     374     6792825 :         if (bn->bn_start <= start) {
     375     6792825 :                 if (bn->bn_last < last)
     376           0 :                         *len = bn->bn_last - start + 1;
     377     6792825 :                 return true;
     378             :         }
     379           0 :         *len = bn->bn_start - start;
     380           0 :         return false;
     381             : }
     382             : 
     383             : /*
     384             :  * Find the first set bit in this bitmap, clear it, and return the index of
     385             :  * that bit in @valp.  Returns -ENODATA if no bits were set, or the usual
     386             :  * negative errno.
     387             :  */
     388             : int
     389       11191 : xbitmap_take_first_set(
     390             :         struct xbitmap          *bitmap,
     391             :         uint64_t                start,
     392             :         uint64_t                last,
     393             :         uint64_t                *valp)
     394             : {
     395       11191 :         struct xbitmap_node     *bn;
     396       11191 :         uint64_t                val;
     397       11191 :         int                     error;
     398             : 
     399       11191 :         bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
     400       11191 :         if (!bn)
     401             :                 return -ENODATA;
     402             : 
     403           2 :         val = bn->bn_start;
     404           2 :         error = xbitmap_clear(bitmap, bn->bn_start, 1);
     405           2 :         if (error)
     406             :                 return error;
     407           2 :         *valp = val;
     408           2 :         return 0;
     409             : }
     410             : 
     411             : /* Count the number of set regions in this bitmap. */
     412             : uint64_t
     413        9421 : xbitmap_count_set_regions(
     414             :         struct xbitmap          *bitmap)
     415             : {
     416        9421 :         struct xbitmap_node     *bn;
     417        9421 :         uint64_t                nr = 0;
     418             : 
     419      111358 :         for_each_xbitmap_extent(bn, bitmap)
     420       46265 :                 nr++;
     421             : 
     422        9412 :         return nr;
     423             : }

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